A former chief UN weapons inspector has compared Prime Minister Tony Blair and George W Bush, the American president, to the Nazi war criminals who started the Second World War.

Scott Ritter, a former US marine, said the US and Britain's "aggressive warfare" in Iraq was similar to German actions in Europe 66 years ago.

"Both these men could be pulled up as war criminals for engaging in actions that we condemned Germany in 1946 for doing the same thing," he said.

He said both leaders would be in a much better position if they had received the backing of the international community by the passing of the infamous second UN resolution.

Mr Ritter also said the "special relationship" between Britain and the US left British honour as nothing more than a "disregarded mistress".

He claimed the sharing of information was a one-way system with the US benefiting from UK intelligence. He said: "Britain gets nothing, other than to say they are America's closest ally in Europe."

Mr Ritter, who was a UN weapons inspector in Iraq between 1991 and 1998, was speaking at Chatham House, the Royal Institute of International Affairs in London.

Mr Ritter told how he delivered a report in 1992 stating that Iraq's missile programme had been eliminated. But, he said, the news was met with "stony silence" and he was told that Iraq still possessed 200 missiles.

The inspectors returned to track down the weapons which never materialised.

"Ninety percent of the time or more we received full co-operation of the Iraqi government."

But there was understandable Iraqi resistance when US intelligence tried to use the weapons inspectors as a way of gaining inside information on the Iraqis to try and rid them of their leader, he argued.